Barrel vault
Abarrel vault,also known as atunnel vault,wagon vaultorwagonhead vault,is an architectural element formed by the extrusion of a single curve (or pair of curves, in the case of a pointed barrel vault) along a given distance. The curves are typically circular in shape, lending a semi-cylindrical appearance to the total design. The barrel vault is the simplest form of avault:effectively a series ofarchesplaced side by side (i.e., one after another). It is a form ofbarrel roof.
As with allarch-based constructions, there is an outward thrust generated against the walls underneath a barrel vault. There are several mechanisms for absorbing this thrust. One is to make the walls exceedingly thick and strong – this is a primitive and sometimes unacceptable method. A more elegant method is to build two or more vaults parallel to each other; the forces of their outward thrusts will thus negate each other. This method was most often used in construction of churches, where several vaultednavesran parallel down the length of the building. However, the outer walls of the outermost vault would still have to be quite strong or reinforced bybuttressing.The third and most elegant mechanism to resist the lateral thrust was to create an intersection of two barrel vaults at right angles, thus forming agroin vault.
Barrel vaults are known from theAncient Iran(Elam), IndianIndus Valley civilizationandAncient Egypt,and were used extensively inRoman architecture.They were also used to replace theCloaca Maximawith a system of underground sewers. Other early barrel vault designs occur in northernEurope,Turkey,Morocco,and other regions. InmedievalEurope, the barrel vault was an important element of stone construction inmonasteries,castles,tower housesand other structures. This form of design is observed incellars,crypts,longhallways,cloistersand evengreat halls.
Theory and early history
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Barrel vaulting was known and utilized by early civilizations, includingancient EgyptandMesopotamia.However, it apparently was not a very popular or common method of construction within these civilizations. The Persians and the Romans were the first to make significant architectural use of them. The technique probably evolved out of necessity to roof buildings with masonry elements such as bricks or stone blocks in areas where timber and wood were scarce. The earliest known example of a vault is atunnel vaultfound under theSumerianzigguratatNippurinBabylonia,ascribed to about 4000 BC, which was built from fired bricks amalgamated withclaymortar.The earliest tunnel vaults in Egypt are found atRequagnahandDenderah,from around 3500 BC in thepredynasticera. These were built withsun-dried brickin three rings over passages descending totombswith aspanof only two metres.[1]In these early instances, the barrel vault was chiefly used for underground structures such as drains andsewers,though several buildings of the great Late Egyptianmortuarypalace-templeofRamesseumwere also vaulted in this way.[2]Recentarchaeologicalevidence discovered at theMorgantinasite (in the province ofEnna) shows that the aboveground barrel vault was known and used in HellenisticSicilyin 3rd century BC, indicating that the technique was also known toancient Greeks.
The vaulted roof of an early Harappan burial chamber has been noted fromRakhigarhi.[3]S.R Raoreports vaulted roof of a small chamber in a house fromLothal.[4]Barrel vaults were also used in the Late HarappanCemetery H culturedated 1900 BC-1300 BC which formed the roof of the metal working furnace, the discovery was made byVatsin 1940 during excavation atHarappa.[5][6][7]
Ancient Romans most probably inherited their knowledge of barrel vaulting fromEtruscansand the Near East. Persians and Romans were the first to use this building method extensively on large-scale projects and were probably the first to usescaffoldingto aid them in construction of vaults spanning over widths greater than anything seen before. However, Roman builders gradually began to prefer the use ofgroin vault;though more complex to erect, this type of vault did not require heavy, thick walls for support (see below), and thus allowed for more spacious buildings with greater openings and much more light inside, such asthermae.
After the fall of theRoman empire,few buildings large enough to require much in the way of vaulting were built for several centuries. In the earlyRomanesqueperiod, a return to stone barrel vaults was seen for the first great cathedrals; their interiors were fairly dark, due to thick, heavy walls needed to support the vault. One of the largest and most famous churches enclosed from above by a vast barrel vault was the church ofCluny Abbey,built between the 11th and 12th centuries.
In 13th and 14th centuries, with the advance of the newGothicstyle, barrel vaulting became almost extinct in constructions of great Gothic cathedrals;groin vaultsreinforced by stone ribs were mostly used in the beginning, and later on various types of spectacular, ornate and complex medieval vaults were developed. However, with the coming of theRenaissanceand theBaroquestyle, and revived interest in art and architecture of antiquity, barrel vaulting was re-introduced on a truly grandiose scale, and employed in the construction of many famous buildings and churches, such asBasilica di Sant'Andrea di MantovabyLeone Battista Alberti,San Giorgio MaggiorebyAndrea Palladio,and perhaps most glorious of all,St. Peter's Basilicain Rome, where a huge barrel vault spans the 27 m (89 ft)-wide nave.[8]
Engineering issues
[edit]With a barrel vault design the vectors of pressure result in a downward force on the crown while the lower portions of the arches realise a lateral force pushing outwards.[9]As an outcome this form of design is subject to failure unless the sides are anchored or buttressed to very heavy building elements or substantial earthwork sidings. For example, atMuchalls CastleinScotland,adjacent walls to the barrel vaulted chambers are up to 4.6 m (15 ft) thick, adding the buttressing strength needed to secure the curved design.
The inherent difficulty of adequately lighting barrel vaulted structures has been widely acknowledged.[10]The intrinsic engineering issue is the need to avoidfenestrationpunctures in stonework barrel vaults. Such openings could compromise the integrity of the entire arch system. Thus the Romanesque medieval builders had to resort to techniques of small windows, large buttresses, or other forms of interior wall cross-bracing to achieve the desired lighting outcomes. In many of the monasteries, a natural solution was cloisters which could have high barrel-vaulted construction with an open courtyard to allow ample lighting.
Since 1996structural engineershave appliedNewtonianmechanics to calculate numeric stress loads for ancient stonework barrel vaults.[11]These analyses have typically used afinite elementalgorithm to calculate gravity induced stresses from the self weight of an arched system. In fact, for structural engineers, analysis of the barrel vault has become a benchmark test of a structural engineeringcomputer model"because of the complex membrane and inextensional bending states of stress" involved.
In terms of comparison to other vaulting techniques, the barrel vault is inherently a weaker design compared to the more complexgroin vault.The barrel vault structure must rest on long walls creating less stable lateral stress, whereas the groin vault design can direct stresses almost purely vertically on the apexes.[12]
Early occurrences
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- Palace of Ardeshir,Iran,Fars province
- Qal'eh Dokhtar,Iran,Firuzabad, Fars
- Sarvestan Palace,Iran,Sarvestan
- Bishapur,Iran,Kazerun,most notably at the Temple of Anahita
- Beverston Castle,England,undercroftbelow south tower of west range
- CathedralofCortona,Tuscany
- Dunnottar Castle,Scotland,WhigsVault
- Hadrian's Villa,Tivoli, Italy,numerous occurrences at this early 2nd century AD site
- Mausoleum of Galla Placidia,Ravenna,Italy(c. 500 AD)
- Muchalls Castle,Scotland,cryptand long hall
- Myres Castle,Scotland,cellars
- Real Monasterio de Nuestra Senora de Rueda,Spain,cloistersof this 12th-centurymonastery
- Scrovegni Chapelalso known asCappella degli Scrovegni,Padua,Veneto,Italy(1303 AD)
- Vatican grotto,Vatican City
Modern examples
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There are numerous contemporary examples of barrel vault design inVictorianandmodern architecture,including:
- Sistine Chapel,Vatican City
- Royal Granary,Meknes,Morocco(17th century)
- Williamson Tunnels,Liverpool,England(early 19th century)
- Belfast,Northern Ireland,City HallBanquetroom with barrel vault ceiling 1896–1906,DonegalSquare[13]
- Huntington Bank Building,Cleveland, Ohio,1924 design
- Kimbell Art Museum,Fort Worth, Texas,United States,spanning a width of 174 feet.
- Melbourne,Australia,Forest Hill Chase Shopping Centre,made ofpolycarbonate
- TheIndiana Universitynewlibrary[14]
- Fremont Street Experience,Las Vegas
In unconventional usage
[edit]Beyond the classical use of the barrel vault in macro-architectural design (e.g. as a major structural roofing element), there are a variety of derivative applications clearly based on the original concept and shape of the barrel vault. These applications arise in the fields ofsurgery,skylightdesign, children's toys and microstructure design (such as bus shelters). While none of these applications rival the majesty of the ancient and Classical predecessors, they demonstrate the pervasiveness of the barrel vault as an architectural concept in contemporary times.
In the field of bone surgery the technique of a "barrel vault" shaped incision is not only a well-definedstate-of-the-artsurgical procedure, but the namebarrel vaultis given to this technique byorthopedicsurgeons.[15]The Wohlfahrt study cited documents results of this surgical procedure on the humantibiain 91 such operations.
See also
[edit]References
[edit]- General
- Roth, Leland M (1993).Understanding Architecture: Its Elements History and Meaning.Oxford, UK: Westview Press. p.29.ISBN0-06-430158-3.
- Specific
- ^One or more of the preceding sentences incorporates text from a publication now in thepublic domain:Spiers, Richard Phené(1911). "Vault".InChisholm, Hugh(ed.).Encyclopædia Britannica.Vol. 27 (11th ed.). Cambridge University Press. p. 956.
- ^Dietrich Wildung,Egypt, From Prehistory to the Romans,Taschen, 2001.
- ^McIntosh, Jane (2008).The Ancient Indus Valley: New Perspectives.ABC-CLIO. p. 293.ISBN978-1-57607-907-2.
- ^Rao, Shikaripur Ranganatha; Rao, Calyampudi Radhakrishna (1973).Lothal and the Indus Civilization.Asia Publishing House. p. 77.ISBN978-0-210-22278-2.
- ^Tripathi, Vibha (27 February 2018)."METALS AND METALLURGY IN THE HARAPPAN CIVILIZATION"(PDF).Indian Journal of History of Science:279–295.
- ^Kenoyer, J.M; Dales, G. F.Summaries of Five Seasons of Research at Harappa (District Sahiwal, Punjab, Pakistan) 1986-1990.Prehistory Press. pp. 185–262.
- ^Kenoyer, J.M.; Miller, Heather M..L.Metal Technologies of the Indus Valley Tradition in Pakistan and Western India(PDF).p. 124.
- ^"St. Peter's - the Nave".Archivedfrom the original on 2006-10-14.Retrieved2006-11-19.
- ^"Mount Holyoke college, The Art of Cathedrals: Stresses in barrel vaulted design".Mtholyoke.edu.Archivedfrom the original on 2014-05-02.Retrieved2014-05-01.
- ^Friedrich Ragette,Traditional Domestic Architecture of the Arab Region,American University of Shadah (2003)
- ^Gui-Rong Liu,Mesh Free Methods: Moving Beyond theFinite ElementMethod,CRC Press (2003)
- ^Robert A. Scott,The Gothic Enterprise: A Guide to Understanding the Medieval CathedralUniversity of California Press (2003)
- ^"Victorian architecture".Victorianweb.org. 2006-09-12.Archivedfrom the original on 2015-02-18.Retrieved2014-05-01.
- ^Indiana University new library description[permanent dead link]
- ^A. Wohlfahrt, P. Heppt, A. Goldmann and P. Wirtz,High tibial barrel-vault osteotomy. A clinical study and statistical analysis of 91 long-term resultsPZ Orthop Ihre Grenzgeb. 1991 Jan–Feb; 129(1):72–79
External links
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